Japan's Cosmetic Regulations: Cosmetics vs. Quasi-Drugs and the Positive List System

Japan operates one of the most distinctive cosmetic regulatory frameworks in the world. Unlike the US or EU, Japan employs a three-tier system — pharmaceuticals, quasi-drugs, and cosmetics — where the middle tier (quasi-drugs) allows specific functional claims that would be impermissible for regular cosmetics. Understanding this system is essential for interpreting Japanese product labels, understanding why the same ingredient may be found at different concentrations across international versions of a product, and appreciating the regulatory rationale behind Japan's approach to cosmetic safety.

The Legal Framework: PMD Act

Japan's cosmetic and pharmaceutical industries are regulated under the Act on Securing Quality, Efficacy and Safety of Products Including Pharmaceuticals and Medical Devices, commonly referred to as the PMD Act (formerly the Pharmaceutical Affairs Law). The PMD Act is overseen and enforced by the MHLW (Ministry of Health, Labour and Welfare, 厚生労働省), with implementation managed at the prefectural level.

The PMD Act establishes three product categories relevant to skincare:

• Pharmaceuticals (医薬品): Prescription and OTC drugs. Claims of treating, preventing, or curing conditions. Strict premarket approval required.
• Quasi-drugs (医薬部外品): Products with specific approved functional effects. Premarket notification or approval required depending on the product type. Active ingredients must be from an approved positive list.
• Cosmetics (化粧品): Products intended to clean, beautify, or promote attractiveness with only mild physiological effects. Manufacturers register at the prefectural level; no premarket efficacy review, but ingredient restrictions apply.

Cosmetics (化粧品): Definition and Limitations

Under the PMD Act, a cosmetic is defined as a product intended to be applied to the human body by rubbing, sprinkling, or similar methods, for the purposes of cleansing, beautifying, promoting attractiveness, or altering appearance — provided the action on the body is mild.

The critical constraint for cosmetics is on claims: a cosmetic can claim to moisturise, cleanse, soften, or improve the appearance of skin. It cannot claim to treat acne, suppress melanin production, reduce hair loss, or prevent body odour. Making such a claim — even if true — reclassifies the product as a quasi-drug or pharmaceutical, triggering a different regulatory pathway.

Cosmetic manufacturers in Japan must comply with the Cosmetics Standard (化粧品基準), a ministerial ordinance that specifies:

• A positive list of permitted preservatives with maximum concentrations
• A positive list of permitted UV filters with maximum concentrations
• A positive list of permitted colouring agents
• A negative list of prohibited and restricted substances

Ingredients not on prohibited or restricted lists that are not in one of the three positive lists can be used freely in cosmetics, provided they are not being used as functional actives in a quasi-drug capacity.

Quasi-Drugs (医薬部外品): The Middle Tier

The quasi-drug category is where Japan's regulatory framework diverges most substantially from the EU and US approaches. Quasi-drugs occupy a defined middle space: they are not as strictly controlled as pharmaceuticals, but they make specific functional claims that ordinary cosmetics cannot.

Common quasi-drug categories in skincare include:

• Whitening products (美白): Products claiming to suppress melanin production or lighten existing pigmentation
• Anti-hair loss products (育毛剤): Products claiming to prevent hair loss or promote regrowth
• Acne treatment products (にきび防止): Products claiming to treat or prevent acne
• Body odour / perspiration control products
• Dental products with specific fluoride claims

For each quasi-drug category, the MHLW maintains a positive list of approved active ingredients — only ingredients on this list can be used as the functional actives in those products. Active ingredients must be used within approved concentration ranges. The product formulation and label claims must be reviewed and approved (or notified, for products in lower-risk categories) by the MHLW before market entry.

Whitening Actives: Japan's Approved Positive List

The whitening quasi-drug category (美白有効成分) is particularly important for international skincare brands, because "whitening" or "brightening" claims are popular globally but regulated with particular specificity in Japan. The following table summarises key MHLW-approved whitening actives as of recent updates:

Ingredient (INCI)	Japanese Name	Mechanism	Approved Max. Concentration (approx.)
Niacinamide	ニコチン酸アミド	Inhibits melanosome transfer to keratinocytes	5%
Kojic acid	コウジ酸	Tyrosinase inhibitor	1%
Arbutin	アルブチン	Tyrosinase inhibitor	7%
Alpha-Arbutin	α-アルブチン	Tyrosinase inhibitor	2%
Magnesium ascorbyl phosphate	リン酸L-アスコルビルマグネシウム	Antioxidant; reduces melanin formation	3%
Ascorbyl glucoside	L-アスコルビン酸2-グルコシド	Stabilised vitamin C derivative	2%
Tranexamic acid	トラネキサム酸	Inhibits plasmin activity; reduces melanin stimulation	2%
Ellagic acid	エラグ酸	Tyrosinase inhibitor; antioxidant	0.5%

Note: Exact approved concentrations may vary by product category and are subject to MHLW revision. Manufacturers must consult current MHLW notifications for precise regulatory limits.

Preservative Regulation: Japan's Positive List System

Unlike the EU (which uses a combination of positive and negative lists) and the US (which relies primarily on safety substantiation with fewer specific limits), Japan employs a strict positive list system for preservatives. Only preservatives specifically listed in the Cosmetics Standard may be used in cosmetics, and each listed preservative has a defined maximum concentration.

Key examples from Japan's preservative positive list:

Preservative	Japan Max. Concentration	EU Max. Concentration	US Limit
Methylparaben	1.0%	0.4% (single); 0.8% (mixed parabens)	No specific limit (CIR safe)
Phenoxyethanol	1.0%	1.0%	No specific limit (CIR safe)
Benzalkonium chloride	0.05% (face); 0.1% (rinse-off)	Restricted; varies by use	Regulated as OTC drug active in some uses
DMDM hydantoin	Listed; concentration restricted	0.6%	No specific limit

Ingredient Naming: INCI vs. Japanese Names

The International Nomenclature of Cosmetic Ingredients (INCI) system — which provides standardised Latin and English ingredient names used in EU and US product labels — has not been fully adopted in Japan. Japanese cosmetic labels use ingredient names from the database maintained by the Japanese Cosmetic Industry Association (JCIA), known as the Japan Cosmetic Ingredient Database (JCID).

Some ingredients share the same name in INCI and JCID notation, while others differ. Additionally, Japanese ingredient names on labels may be written in Japanese script (hiragana, katakana, or kanji), which can make cross-referencing difficult for consumers and formulators unfamiliar with the system. For example:

• INCI "Glycerin" = Japanese "グリセリン" (glycerin, same)
• INCI "Niacinamide" = Japanese "ニコチン酸アミド" (nicotinamide, different common name)
• INCI "Sodium Hyaluronate" = Japanese "ヒアルロン酸Na" (abbreviated form)
• INCI "Butylene Glycol" = Japanese "BG" (common abbreviation used on Japanese labels)

For international brands seeking entry to the Japanese market, ensuring that all ingredient names on labels comply with JCID notation — and that Japanese-language label requirements are met — is a necessary step in the product registration process.

How International Brands Adapt for Japan

Global brands selling in Japan frequently encounter the following situations requiring formulation or labelling adaptation:

• Claim reformulation: A product sold in the EU or US as "brightening" may need to be either registered as a quasi-drug whitening product (with approved actives at approved concentrations) or reformulated to remove the brightening active or claim for the Japanese cosmetic version
• Preservative substitution: A preservative used freely in the US that does not appear on Japan's positive list must be replaced with a listed alternative
• UV filter compliance: Japan's approved UV filter list differs from the EU's; some newer UV filters approved in the EU are not yet approved in Japan, requiring reformulation of sun care products
• Label translation: All ingredient names must be listed in JCID notation; full INCI labels from EU products are not compliant without translation
• Regulatory pathway selection: A product with niacinamide at 5% claiming whitening effects must be registered as a quasi-drug with MHLW notification, not simply sold as a cosmetic

Key Regulatory Distinctions: Japan vs. EU vs. US

Feature	Japan	EU	US
Regulatory body	MHLW	European Commission + Member States	FDA
Middle-tier product category	Quasi-drug (医薬部外品)	None (cosmetic or medicinal)	OTC drug
Whitening claims	Require quasi-drug registration	Permitted in cosmetics with substantiation	May require OTC drug status if drug claim made
Preservative system	Strict positive list with concentration limits	Positive list (Annex V) with concentration limits	No positive list; safety substantiation required
Ingredient naming	JCID (Japanese names)	INCI (mandatory)	INCI (required)
Premarket approval	Required for quasi-drugs; notification for cosmetics	Responsible person notification; no premarket approval for cosmetics	No premarket approval for cosmetics

Key Takeaways

• Japan's quasi-drug tier allows specific functional claims (whitening, anti-hair loss) that regular cosmetics cannot make, and requires MHLW approval of active ingredients from an official positive list
• Approved whitening actives in Japan include niacinamide, kojic acid, arbutin, alpha-arbutin, and several vitamin C derivatives, each with defined concentration limits
• Japan uses a positive list for preservatives — only listed ingredients at listed concentrations may be used; this differs from the US approach
• INCI is not fully adopted; Japanese labels use JCID names, requiring translation for international brands
• International brands must carefully assess whether their formulation and claims require quasi-drug registration before entering the Japanese market